Fiber compound material

ABSTRACT

The fiber compound material contains at least one fiber component ( 1 ) and at least two matrix components ( 2, 3 ) of different material classes which have different thermo-mechanical properties. In a manufacture of the compound material two matrix components can be liquefied and fiber filaments ( 1 ) of the fiber component can be wetted by the liquefied matrix components. In this in the liquefied state the one matrix component is not soluble in the other. In a consolidation of the compound material one of the previously liquefied matrix components ( 3 ) can be hardened out irreversibly to a duroplastic whereas the other of the previously liquefied matrix components ( 2 ) remains meltable.

[0001] The invention relates to a fiber compound material comprising atleast one fiber component and to a use of the fiber compound material.

[0002] Compound materials of this kind have fiber filaments and a matrixconsisting of cross-linking or non cross-linking plastics.

[0003] In the manufacture of a compound material by means of a pressureimpregnation the fiber filaments are immersed in the form of fiberstrands in a bath with a dispersion consisting of water and polymerparticles, with the material for a thermoplastic matrix being introducedbetween the fiber filaments with the particles. The particles distributethemselves in the fiber strands. The water which is taken up by thefiber strands is evaporated in a drying process. Then the polymerparticles which are distributed in the fiber strands are melted, withthe melt distributing itself uniformly in the fiber strands. A maximumwetting takes place between pair-wise arranged rollers, with a coolingdown and a hardening of the matrix taking place at the same time.

[0004] In this material the low compression strength in the fiberdirection and the poorer capability of adhesive bonding with othermaterials is considered disadvantageous.

[0005] The object of the invention is to improve a compound materialwith respect to the named disadvantages. This object is satisfied inaccordance with the invention by the features of claim 1.

[0006] The fiber compound material contains at least one fiber componentand at least two matrix components of different material classes whichhave different thermo-mechanical properties. In a manufacture of thecompound material, two matrix components can be liquefied and fiberfilaments of the fiber component can be wetted by the liquefied matrixcomponents. In this in the liquefied state the one matrix component isnot soluble in the other. In a consolidation of the compound materialone of the previously liquefied matrix components can be hardened outirreversibly to a duroplastic whereas the other of the previouslyliquefied matrix components remains meltable.

[0007] Subordinate claims 2 to 8 relate to advantageous embodiments ofthe fiber compound material in accordance with the invention. Uses ofthe fiber compound material in accordance with the invention are thesubject of claims 9 and 10.

[0008] In the following the invention will be explained with referenceto the enclosed FIGURE. The sole FIGURE shows a section of an embodimentof a fiber compound material in accordance with the invention in aspatial illustration.

[0009] The fiber compound material is manufactured on the basis of theabove described manufacturing process from fiber strands which consistof fiber filaments 1, and of particles of a thermoplastic 2 and aduroplastic 3. In a preferred embodiment, fiber material consisting ofcarbon, particles of polyamide and particles of warm hardening epoxyresin are used. The fiber strands are impregnated in a bath with theparticles of polyamide and epoxy resin, with it being possible for theproportion of the epoxy resin in relation to the plastic proportion tolie in the range from 3 to 30% by volume. In the impregnation theparticles of polyamide and epoxy resin can also be worked in into thefiber strands separately from one another. It is advantageous when atenside is used for the reduction of the surface tension of the water.After the evaporation of the water the connection of the threecomponents takes place in a downstream oven. Through the heating theparticles of polyamide and epoxy resin are melted; the melts propagatein the fiber strands through the capillary action and wet the fiberfilaments 1. The epoxy resin hardens out whereas the polyamide remainssoft for the consolidation. In the consolidation the polyamide issolidified through cooling down.

[0010] As the FIGURE shows, a body is produced in which thethermoplastic particles 2 and the duroplastic particles 3 are connectedwith one another and with the fiber filaments 1; at the surface of thebody there are regions which consist of thermoplastic and duroplastic.As a result of the regions of duroplastic the body can be connected withother bodies by means of adhesive bonding. As a result of the fact thatthe duroplastic also wets the fibers and has a higher elasticity modulethan the thermoplastic (for example polyamide), a higher compressionstrength is achieved in the fiber direction.

[0011] It is also possible after the melting to retain the liquid formof the matrix components, to press the latter and to cool down theliquid matrix components and to solidify at least one or both.

[0012] In a second embodiment of the fiber compound material, inaddition to the fiber strands a first matrix component of thermoplastic,e.g. polyimide, and a second matrix component of metal, e.g. aluminumalloys, are used. The metallic alloy advantageously has a low meltingpoint so that it can be melted during the manufacture of the compoundmaterial and during a later reshaping.

[0013] The compound material in accordance with the invention can alsocontain at least three matrix components, with the first matrixcomponent being a thermoplastic, the second matrix component aduroplastic and the third a metal or another inorganic material.

[0014] The fiber components of the compound material in accordance withthe invention can be present in the form of a fabric or mesh of fiberstrands. A compound material of this kind can be formed to besemi-flexible. A semi-flexibility is present when the fiber strandswhich extend in a predetermined direction have a relatively smallproportion of matrix components and this proportion is so small that thecompound material is relatively easy to bend in the named direction atambient temperature.

[0015] The compound material can be used to reinforce the surface of abody through adhesive bonding on. In this an adhesive bonder is used forthe adhesive bonding on which enters into a substantially strongerbonding with one of the matrix components, in particular a duroplastic,than with another matrix component, in particular a thermoplastic. Thecompound material can be brought through thermoplastic deformation intoa shape which fits onto the surface of the body prior to the adhesivebonding on.

1. Fiber compound material comprising at least one fiber component (1)and at least two matrix components (2, 3) of different material classeswhich have different thermo-mechanical properties, characterized in thatin a manufacture of the compound material two matrix components (2, 3)can be liquefied and fiber filaments (1) of the fiber component can bewetted by the liquefied matrix components; in that in the liquefiedstate the one matrix component is not soluble in the other; and in thatin a consolidation of the compound material one of the previouslyliquefied matrix components (3) can be hardened out irreversibly to aduroplastic whereas the other of the previously liquefied matrixcomponents remains meltable.
 2. Compound material in accordance withclaim 1 , characterized in that the fiber component is present in theform of an endless reinforcement strand of fiber filaments (1); and inthat the matrix components (2, 3) are connected to the fiber componentby means of a pressure impregnation.
 3. Compound material in accordancewith claim 1 or claim 2 , characterized in that the one matrix component(2) is a thermoplastic.
 4. Compound material in accordance with any oneof the claims 1 to 3 , characterized in that the proportion ofduroplastic in relation to the total proportion of the matrix componentslies in the range from 3 to 30% by volume.
 5. Compound material inaccordance with any one of the claims 1 to 4 , characterized in that itcontains a matrix component of a metallic alloy which can be meltedduring the manufacture of the compound material and during a laterreshaping.
 6. Compound material in accordance with any one of the claims1 to 5 , characterized by three matrix components, with the first matrixcomponent (2) being a thermoplastic, the second matrix component (3)being a duroplastic and the third a metal or another inorganic material.7. Compound material in accordance with any one of the claims 1 to 6 ,characterized in that the fiber component (1) is present in the form ofa fabric or a mesh of fiber strands.
 8. Compound material in accordancewith claim 7 , characterized by a semi-flexibility, with the fiberstrands (1) which extend in a predetermined direction having arelatively small proportion of matrix components (2, 3) which is sosmall that the compound material can be relatively easily bent in thenamed direction at ambient temperature.
 9. Use of a compound material inaccordance with any one of the claims 1 to 8 , characterized in that thesurface of a body is reinforced with the compound material throughadhesively bonding on, with an adhesive bonder which is used for theadhesive bonding on entering into a substantially stronger connectionwith one of the matrix components (3), in particular with theduroplastic, than with another matrix component (2), in particular athermoplastic.
 10. Use in accordance with claim 9 , characterized inthat the compound material is brought through thermoplastic deforminginto a shape which fits onto the surface of the body prior to theadhesive bonding on.